Unitized fibrous constructs having functional circumferential retaining elements

ABSTRACT

A unitized fibrous construct for providing reinforcement to castable structures, such as cementitious structures is claimed. The construct includes a bundle of reinforcing fibers or filaments that are held in place prior to addition to the cementitious mixture by a retaining element. The retaining element is of such a composition that upon release into the cementitious mixture it provides reinforcing capability to the cement structure. As such, the construct adds additional reinforcing capability and diminishes the likelihood of detrimental side-effects attributed to retaining elements that otherwise dissolve or disperse in the cementitious mixture.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of U.S. provisional application No.60/603,091, filed on Aug. 20, 2004.

FIELD OF THE INVENTION

The present invention is directed to unitized fibrous constructs forreinforcing castable mixtures, such as cementitious matrices or mixturesand, more particularly a unitized fibrous construct in which thecircumferential retaining element that retains a bundle of reinforcingfibers or filaments also serves as a reinforcing element upon mixtureinto the castable mixture.

BACKGROUND OF THE INVENTION

Many proposals have been made to reinforce, strengthen, and/or reducecracking during curing or otherwise beneficially alter the properties ofcastable mixtures, such as cementitious mixtures, by applying and/orincorporating various types of fibrous components, including asbestos,glass, steel, as well as synthetic polymer fibers to aqueous basedconcrete mixes prior to the curing of the concrete. The types of polymerfibers in use or proposed for use include those composed of natural andsynthetic composition. As is evident in the prior art, individualfibrous components are well known in terms of their performancemodifying attributes. Relatively large diameter fibers, for example, inexcess of 40 to 60 microns in diameter, can be added to a cementitiousmixture such as a wet concrete blend, dispersed in the blend bymechanical agitation, followed by pouring and curing of the concrete.Large diameter fibers serve to reinforce the concrete after it has beencured, by providing additional tensile strength and minimizing impactdamage and crack propagation. Small diameter fibers, typically less than30 to 40 microns in diameter, and having a relatively high surface area,are commonly added to concrete mixes in order to reduce the developmentof small elastic shrinkage cracks in the concrete during the curingperiod. The problem of crack development is known to occur as a resultof uneven curing of the concrete. The fibrous components used typicallyin the practice of reinforcing cementitious mixtures includespecifically thermoplastic synthetic fibers of finite staple length,such as polypropylene staple fibers.

Due to the variable and unpredictable form conventional reinforcingfibrous components have heretofore been provided for end-useconsumption, such as at a construction work-site, the accurate andreproducible dosing of reinforcing fibrous component into sequentialbatches of cementitious mixtures has been dubious at best. Furthercomplicating the actual utilization of the reinforcing fibrouscomponents, numerous synthetic thermoplastic polymers used in theformation of suitable staple fibers are inherently hydrophobic innature. As a result, difficulties can arise in obtaining a uniformdispersion and blending of the reinforcing fibrous component throughouthydrous cementitious mixtures using conventional mixing equipment.

Prior attempts to address the issue described have focused on the use ofbinding agents. U.S. Pat. No. 5,399,195, entitled, “Fibres and materialcomprising the same”, issued on Mar. 21, 1995, in the name of inventorsHansen et al., discloses the addition of small amounts of fine (lessthan 30 microns) polymer fibers to concrete. During production, thefilaments are treated with a topical wetting agent. After the filamentsare chopped into staple-length fibers, the wetting agent holds or bindsthe staple fibers together in the form of micro-bundles. Themicro-bundles remain relatively stable during handling, and when thefibers are added to the concrete mix, the wetting agent promotesdispersion of the fibers. U.S. Pat. No. 6,258,159, entitled, “Productand method for incorporating synthetic polymer fibers into cementmixtures”, issued on Jul. 10, 2001, in the name of inventor Pyle,attempts to address the forming of micro-bundles of fibers byincorporation of binding agents into the staple fibers themselves duringthe melt-extrusion process.

The use of binding agents, whether internal or externally applied, whileimproving in-part issues inherent of individual staple fibers, suchpractices have not obviated such problems as random agglomerate size,and further, the use of binding agents has introduced additionalproblems. Most notably, the corresponding performance of the bindingagent is based upon application of the binding agent to thereinforcement fibrous components such that the binding agent is bothuniformly applied to the majority of the fibers so as to obtainequivalency within the batch, and that no excess binding agent isintroduced as such will adversely effect the ability of thereinforcement fibrous components to disengage and distributehomogeneously. One other determent encountered in the use of bindingagents is that air is often entrained within the micro-bundles uponapplication and agglomeration of the staple fibers. When suchmicro-bundles are subjected to mechanical mixing, the entrained air isreleased as a foam, which reasonably compromises the ability of thecementitious mixture to cure uniformly.

Cellulosic tapes have also been utilized to retain reinforcement fibers;however, such tapes can become problematic for a cementitious matrix ormixture as well. See for example U.S. Pat. No. 5,807,458, entitled,“Reinforcing Elements for Castable Compositions”, issued Sep. 15, 1998,in the name of inventors Sanders et al. The cellulose tape is prone todegradation in the alkaline environment of the mixture. Degradation ofthe tapes may introduce void spaces within the mixture which cannegatively impact uniform curing of the cement. Further, the wetcellulose tapes can promote mold growth within the mixture that can leadto cracks in the setting mix.

More recently, circumferential binding elements have been utilized toprovide temporary retention of fibrous constructs, as disclosed incommonly assigned U.S. Patent Publication 2004/0244653, entitled“Unitized Fibrous Concrete Reinforcement”, filed on Dec. 9, 2004, in thename of inventors Schmidt et al, which is herein incorporated byreference as if set forth fully herein. Heretofore, the circumferentialbinding element was purposeful as a retaining element, but did notcontribute incremental functionality within the cementitious matrix.

As is evident in the industry, an unmet need exists for a means ofintroducing reinforcing fibrous components into a cementitious mixturesuch that the reinforcing fibrous components exhibit the attributes ofuniform and predictable presentation for use, while the circumferentialretaining elements, which temporarily bind the oriented fibrouscomponents, further provide an advantageous and incremental performancewithin the cementitious matrix.

SUMMARY OF THE INVENTION

The present invention is directed to unitized fibrous constructs forreinforcement in a castable compound, such as a cementitious matrices ormixtures. The invention provides for a construct that includes a bundleof reinforcing fibers or filaments surround, at least partially, by aretaining element, which also serves the dual purpose, upon addition tothe cementitious mixture, of acting as a reinforcing element. In thisregard, the retaining element does not need to dissolve or otherwise bedispersible upon addition to the cementitious mixture. As such,degradation issues with dispersible materials are eliminated, such asissues related to void spaces in the mixture and possible mold issuesleading to crack propagation. In addition, by creating a construct inwhich the retaining element serves as a reinforcing element furtherstrengthening and stability of the overall cementitious mixture isimparted from a single unitized fibrous construct.

In one embodiment of the invention a unitized fibrous construct forreinforcing a cementitious mixture includes a plurality of reinforcingfilaments or fibers oriented in a generally parallel relationship suchthat the plurality of reinforcing filaments or fibers form a unit havinga circumferential exterior surface. The unit will those typically formthe geometry of a cylindrical bundle of filaments or fibers, althoughother geometries of the unit are herein contemplated and within thebounds of the present invention. The construct also includes a retainingelement that serves as a reinforcing element in the cementitiousmixture. The retaining element surrounds at least a portion of thecircumferential exterior surface and retains the plurality ofreinforcing filaments or fibers prior to adding the construct to thecementitious mixture. Thus, once the construct is formed, thecircumferential retaining element aids in maintaining the integrity ofthe unitized fibrous construct, and the fibrous component therein, forpurposes of shipment, measurement, and dosing into a cementitiousmixture. Typically the retaining element will be spirally wound aroundthe plurality of fibers or filaments, such that the retaining elementprovides temporal retention of the bundle of fibers or filaments priorto immersion in the cementitious mixture. In most instances, minimalspiral winding is required, less than about 30% coverage of the surfacearea of the circumferential exterior surface of the unit, so as toinsure that the fibers and filaments become free from containment uponagitation in the cementitious mixture. Upon mechanical agitation of theunitized fibrous construct in a cementitious mixture, thecircumferential retaining element is disrupted, allowing for thehomogenous release, distribution, and dispersion of the reinforcingfilaments and fibers into the overall cementitious mixture and releaseof the circumferential retaining element itself into the mixture, whichalso serves as a reinforcing element.

Typically, the retaining element will be formed of a similar material,and in some embodiments the identical material, as is used to form thereinforcing fibers or filaments. The circumferential retaining elementmay be selected from suitable materials that are considered structurallybeneficial to a cementitious matrix by providing additionalreinforcement, minimize impact damage, and crack propagation. Suchfibrous or filamentary material at least partially or may entirelyinclude super absorbent polymers, splittable fiber or filaments, andfiber or filaments with three-dimensionality, such as coiled or crimped.Further, such materials may consist of thermoplastic, thermoset andpartially soluble resins, which are subject to mechanical failure when acorresponding stress and/or solvency threshold is exceeded. The materialselected may also be mechanically modified, as exemplified byfibrillation, drawing, perforation, crimping, embossing or molding, soas to exhibit performance attributes in the cementitious matrix such asa reinforcement or elastic shrinkage crack reduction.

Various geometries may be employed in the application of thecircumferential retaining element, including without limitation,continuous or discontinuous filaments, ribbons, or sheets, whichcircumscribe the combined, essentially parallel reinforcing fibrouscomponents. It is within the purview of the present invention that thecomposition of the circumferential retaining elements and of one or moreof the reinforcing fibrous components need not necessarily be the same.

It is further within the purview of the present invention that theretaining element may be placed under additional tension by means oftwisting the retaining element. Placing additional tension on theretaining element facilitates the mechanical removal of the retainingelement upon mechanical agitation, which then enhances the fiberdistribution within a cementitious mixture.

It is also noted that while the present embodiment includes a singleretaining element it is possible, and within the inventive conceptsherein disclosed, for more than one retaining element to be used inconnection with a single unitized reinforcing construct. For example,two reinforcing elements may be spirally wound around the unit of fibersor filaments in a double-helix type arrangement.

The reinforcing filaments are continuous filaments and in fiberembodiments the fibers are finite staple-length fibers. Additionally,the reinforcing filaments may be characterized as fibrillatedreinforcing filaments. The reinforcing filaments or fibers may beimparted with tension during processing to insure that the degree ofdispersion necessary occurs once the bundle of filaments or fibers arefree from retention within the cementitious mixture. In alternateembodiments the reinforcing filaments or fibers may be splittablefilaments or fibers or may be formed from a super absorbent polymercomposition.

In another embodiment the unitized fibrous construct for reinforcing acementitious mixture includes a plurality of reinforcing filaments orfibers oriented in a generally parallel relationship such that theplurality of reinforcing filaments or fibers form a unit having acircumferential exterior surface. The construct also includes aretaining element formed of one or more splittable filaments thatsurround at least a portion of the circumferential exterior surface andretains the plurality of reinforcing filaments or fibers prior to addingthe construct to the cementitious mixture. Typically, the splittablefilaments will provide reinforcing capabilities once they have beenadded to the cementitious mixture

The reinforcing filaments or fibers may have a composition similar to oridentical to the composition of the splittable filament retainingelement. Additionally, the plurality of reinforcing filaments or fibersmay be defined as fibrillated reinforcing filaments, which may beimparted with tension to further encourage dispersion upon release fromthe retaining element. The reinforcing filaments or fibers may furtherbe defined as being formed from a super absorbent polymer composition.

In yet another embodiment the unitized fibrous construct for reinforcinga cementitious mixture includes a plurality of reinforcing filaments orfibers oriented in a generally parallel relationship such that theplurality of reinforcing filaments or fibers form a unit having acircumferential exterior surface. The construct also includes aretaining element formed of a super absorbent polymer composition thatsurrounds at least a portion of the circumferential exterior surface andretains the plurality of reinforcing filaments or fibers prior to addingthe construct to the cementitious mixture. Typically, the superabsorbent polymer composition retaining elements will providereinforcing capabilities once they have been added to the cementitiousmixture.

The reinforcing filaments or fibers may have a composition similar to oridentical to the composition of the super absorbent polymer compositionretaining element. Additionally, the plurality of reinforcing filamentsor fibers may be defined as fibrillated reinforcing filaments, which maybe imparted with tension to further encourage dispersion upon releasefrom the retaining element. The reinforcing filaments or fibers mayfurther be defined as being formed from a super absorbent polymercomposition.

Thus, the present invention is able to provide for a cementitiousreinforcing construct that includes a retaining element that impartsreinforcing structure into the cementitious mixture. Such a constructbenefits from not having a retaining structure that disperses orotherwise dissolves in the aqueous cementitious mixture and impartspossible negative side-effects to the cementitious mixture, such asvoids, strength reducing mold and the like. Additionally, thereinforcing aspect of the retaining element provides for a constructthat is able to provide additional per unit reinforcement of the cementmixture.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an illustrative embodiment of the unitized fibrous constructof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiments in variousforms, hereinafter the present invention is described by presentlypreferred embodiments with the understanding that the present disclosureis to be considered as an exemplification of the invention, and is notintended to limit the invention to the specific embodiment illustrated.

Referring to FIG. 1, therein is illustrated an embodiment of a unitizedfibrous construct of the present invention. The unitized fibrousconstruct is added to a castable mixture, such as a cementitious mixtureto provide added reinforcement, resulting in greater strength, stabilityand crack-resistance. The unitized fibrous construct 10 is definedherein as a construct including a plurality of oriented reinforcingcontinuous filaments or finite staple length fibers 12. The filaments orfibers 12 are arranged in a general parallel relationship such that thefilaments or fibers form a bundle. While the bundle will typically havea general cylindrical shape, the bundle may also have any other shape,for example oval, square, triangular, etc. The plurality of filaments orfibers 12 will be bundled such that they form a circumferential exteriorsurface 14.

The construct further includes one or more retaining elements 16 thatsurround at least a portion of the circumferential exterior surface 14and serve to retain the reinforcing filaments or fibers 12 prior toadding the construct 10 to a castable mixture, such as a cementitiousmixture. The retaining element will serve as a reinforcing element upononce added to the castable mixture, such as a cementitious mixture.

In order for the retaining element 16 to serve as a reinforcing elementupon addition to the castable mixture the retaining element willtypically be formed of a similar, and in some embodiments identical,fibrous or filamentary material, denier, and length as the reinforcingfibers or filaments 12. Further still, in alternate embodiment theretaining element 16 may be of a dissimilar fibrous or filamentarymaterial, denier, and length as the reinforcing fibers or filaments 12.In those embodiments in which the retaining element is a dissimilarfibrous or filamentary material compared to the reinforcing fibers orfilaments, the retaining element will be formed of a material thatallows for the retaining element to provide reinforcing characteristicsupon addition to the castable mixture.

Typically, the unitized fibrous construct of the present invention isformed from a plurality of reinforcing fibrous or filamentary componentsand one or more circumferential retaining elements. The composition ofsuch reinforcing fibers and circumferential retaining element may beformed from any suitable synthetic polymers, including, but not limitedto, thermoplastic and thermoset polymers, including polyesters,polyolefins, such as polypropylene and polypropylene copolymers,polyethylene and polyethylene copolymers, polyamides, polyimides,polylactic acid, polyhydroxyalkanoate, polyvinyl alcohol, ethylene vinylalcohol, polyacrylates, copolymers thereof, and the combinationsthereof. Additionally the reinforcing fibers or filaments and thecircumferential retaining element may be formed from any suitablenatural fibers, including, but not limited to rayon, cotton, pulp, flax,and hemp and the combinations thereof. A particularly preferredembodiment of the present invention is directed to reinforcing fibers orfilaments including polyolefin thermoplastic resins.

In one embodiment of the invention the retaining element that surroundsa portion of the exterior surface includes splittable filaments, whichmay be of similar or dissimilar polymeric composition in relation to thereinforcing fibers or filaments. Suitable splittable fibers are taughtin U.S. Pat. No. 6,838,402, issued on Jan. 4, 2005, in the name ofinventors Harris, et al.; U.S. Pat. No. 6,746,766, issued on Jun. 18,2004, in the name of inventors Bond, et al.; U.S. Pat. No. 6,743,506,issued on Jun. 1, 2004, in the name of inventors Bond et al.; and U.S.Pat. No. 6,444,312, issued on Sep. 9, 2002, in the name of inventorDugan, all of which are herein incorporated by reference as if set forthfully herein.

In embodiments in which the retaining element is splittable filaments,the plurality of reinforcing filaments may be fibrillated, wherein thefilaments may be fibrillated by any conventional fibrillation technique,such as by mechanical fibrillation described in U.S. Pat. No. 3,302,501,issued on Feb. 7, 1967, in the name of inventor Greene; U.S. Pat. No.3,496,260, issued Feb. 17, 1970, in the name of inventors Guenther etal.; U.S. Pat. No. 3,550,826, issued Dec. 29, 1970; in the name ofinventor Salmela; and U.S. Pat. No. 3,756,484, issued Sep. 4, 1973, inthe name of inventor Guenther, or by fluid and sonic fibrillation asdisclosed in U.S. Pat. No. 3,345,242, issued Oct. 3, 1967, in the nameof inventor Rasmussen, all of which are hereby incorporated by referenceas if set forth fully herein. In addition, the reinforcing filaments maybe imparted with tension by way of twisting the filaments as well.Tension imparted in the reinforcing filaments will cause greaterdispersion of the filaments once the retaining element has been removedfrom the construct/bundle of filaments.

Additionally, in embodiments in which the retaining element issplittable filaments, the plurality of reinforcing fibers or filamentsmay be formed from a super absorbent polymer composition. Exemplarysuper absorbent polymers are disclosed in U.S. Pat. No. 5,145,609,issued Sep. 8, 1992, in the name of inventor Chambers; U.S. Pat. No.4,820,773; issued Apr. 11, 1989, in the name to inventors Alexander etal.; and U.S. Pat. No. 4,645,039, issued Mar. 31, 1997; in the name ofinventor Brandt et al., all of which are herein incorporated byreference as if set forth fully herein.

In another embodiment of the invention the retaining element thatsurrounds a portion of the exterior surface may include a superabsorbent polymer composition. Exemplary super absorbent polymers aredisclosed in the previously referenced and incorporated patents.

In those embodiments in which the retaining element is formed of a superabsorbent polymer composition, the reinforcing fibers may includesplittable fibers. Suitable splittable fibers are taught in thepreviously referenced and incorporated patents.

According to the present invention, the retaining element surrounds atleast a portion of the circumferential exterior surface of theconstruct. Once formed, the retaining element aids in maintaining theintegrity of the unitized fibrous construct, and the reinforcing fibrouscomponent therein, for the purposes of shipment, measurement, and dosinginto a cementitious mixture. Upon mechanical agitation, and optionallyexposure to appropriate solvents, the unitized fibrous construct in acementitious mixture, the retaining element are disrupted, allowing forthe homogenous release, distribution, and disbursement of thereinforcing fibrous component into the overall cementitious mixture. Theunitized fibrous construct of the present invention is believe to reduceplastic shrinkage cracking by at least 10% per ASTM 1399, ObtainingAverage Residual Strength of Fiber Reinforced Concrete.

A number of suitable methodologies exist for the formation of unitizedfibrous constructs in accordance with the present invention. Apreferred, though non-limiting, method is taught in part by U.S. Pat.No. 4,228,641, issued on Oct. 1, 1980, in the name of inventors O'Neil,this patent is herein incorporated by reference as if set forth fullyherein. The '641 O'Neil patent teaches a twine including a core bundleof synthetic monofilaments circumscribed by a synthetic material in athin band form spirally wound about the monofilaments. It has been foundby the inventors of the present invention that by practice of the methodtaught in the '641 O'Neil patent, with subsequent and repeated scissionof the continuous twine construct at or between each iteration of thespiral winding that finite length unitized fibrous constructs are formedwhich are suitable for practice in light of the present invention.

The dimensions of the retaining element is defined in terms of theoverall circumference of the exterior surface formed by the reinforcingfibers or filaments, as based on the quantity and relative denier of theindividual reinforcing fibrous components, and of length, as based onthe greatest finite staple length of the cumulative combination ofreinforcing fibrous components. Suitable overall circumferences andlengths of the circumferential retaining elements formed in accordancewith the present invention may reasonably range from 3 mm to 150 mm andfrom 8 mm to 100 mm, respectively. In a presently preferred embodimentfor standard practices, circumferential retaining elements exhibit anoverall diameter of between 3 mm and 30 mm and lengths of between 12 mmand 50 mm may be utilized. Further, the circumferential retainingelements may exhibit a width preferably about 1%-50% of the totaldiameter of the unitized fibrous construct, more preferably about 3%-40%of the total diameter of the unitized fibrous construct, and mostpreferably about 5%-30% of the total diameter of the unitized fibrousconstruct. Further still, the circumferential retaining element ispreferably about 2%-50% by weight of the unitized construct includingparallelized reinforcement fibers, more preferably of about 6%-40% byweight of the unitized construct, and most preferably of about 8%-30%weight of the unitized construct.

The circumferential retaining element may include one or more continuousor discontinuous filaments, ribbons, or sheets of varying thicknessesthat retain the reinforcing fibrous components by a plurality ofwrapping techniques so as to expose more or less fiber to the externalenvironment. For instance, two thin circumferential retaining elementsmay be used in a double helix wrapping technique, whereby twocircumferential retaining elements criss-cross back and forth about thecircumference of the fibrous components.

Thus, the present invention is able to provide for a cementitiousreinforcing construct that includes a retaining element that impartsreinforcing structure into the cementitious mixture. Such a constructbenefits from not having a retaining structure that disperses orotherwise dissolves in the aqueous cementitious mixture and impartspossible negative side-effects to the cementitious mixture, such asvoids, strength reducing mold and the like. Additionally, thereinforcing aspect of the retaining element provides for a constructthat is able to provide additional per unit reinforcement of the cementmixture.

From the foregoing, it will be observed that numerous modifications andvariations can be affected without departing from the true spirit andscope of the novel concept of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentsillustrated herein is intended or should be inferred. The disclosure isintended to cover, by the appended claims, all such modifications asfall within the scope of the claims.

1. A unitized fibrous construct for reinforcing a cementitious mixture,the construct comprising: a plurality of reinforcing filaments or fibersoriented in a generally parallel relationship such that the plurality ofreinforcing filaments or fibers form a unit having a circumferentialexterior surface; and a retaining element that surrounds at least aportion of the circumferential exterior surface and retains theplurality of reinforcing filaments or fibers prior to adding theconstruct to the cementitious mixture, wherein the retaining elementserves as a reinforcing element in the cementitious mixture.
 2. Theconstruct of claim 1, wherein the plurality of reinforcing filaments andthe retaining element are formed of similar materials.
 3. The constructof claim 1, wherein the plurality of reinforcing filaments furthercomprise a plurality of continuous reinforcing filaments.
 4. Theconstruct of claim 1, wherein the plurality of reinforcing fibersfurther comprises a plurality of finite staple length reinforcingfibers.
 5. The construct of claim 1, wherein the plurality ofreinforcing filaments further comprises a plurality of fibrillatedreinforcing filaments.
 6. The construct of claim 1, wherein theplurality of reinforcing filaments or fibers is further defined as beingimparted with tension to impart greater dispersion upon addition to thecementitious mixture.
 7. The construct of claim 1, wherein the pluralityof reinforcing filaments or fibers further comprise splittablereinforcing filaments or fibers.
 8. The construct of claim 1, whereinthe plurality of reinforcing filaments or fibers further comprise asuper absorbent polymer composition.
 9. The construct of claim 1,wherein the retaining element further comprises a splittable filament orfiber retaining element.
 10. The construct of claim 1, wherein theretaining element further comprises a super absorbent polymercomposition.
 11. The construct of claim 1, wherein the retaining elementcircumscribes no more than 80% of the total surface area of thecircumferential exterior surface.
 12. A unitized fibrous construct forreinforcing a cementitious mixture, the construct comprising: aplurality of reinforcing filaments or fibers oriented in a generallyparallel relationship such that the plurality of reinforcing filamentsor fibers form a unit having a circumferential exterior surface; and aretaining element formed of one or more splittable filaments thatsurrounds at least a portion of the circumferential exterior surface andretains the plurality of reinforcing filaments or fibers prior to addingthe construct to the cementitious mixture.
 13. The construct of claim12, wherein the plurality of reinforcing filaments or fibers furthercomprise filaments or fibers having a composition similar to theretaining element.
 14. The construct of claim 12, wherein the pluralityof reinforcing filaments or fibers further comprise a plurality offibrillated reinforcing filaments.
 15. The construct of claim 14,wherein the fibrillated filaments are further defined as being impartedwith tension.
 16. The construct of claim 12, wherein the plurality ofreinforcing filaments or fibers further comprise a super absorbentpolymer composition.
 17. The construct of claim 12, wherein theplurality of reinforcing filaments or fibers further comprise aplurality of splittable reinforcing filaments.
 18. A unitized fibrousconstruct for reinforcing a cementitious mixture, the constructcomprising: a plurality of reinforcing filaments or fibers oriented in agenerally parallel relationship such that the plurality of reinforcingfilaments or fibers form a unit having a circumferential exteriorsurface; and a retaining element formed of a super absorbent polymercomposition that surrounds at least a portion of the circumferentialexterior surface and retains the plurality of reinforcing filaments orfibers prior to adding the construct to the cementitious mixture. 19.The construct of claim 18, wherein the plurality of reinforcingfilaments or fibers further comprise filaments or fibers having acomposition similar to the retaining element.
 20. The construct of claim18, wherein the plurality of reinforcing filaments or fibers furthercomprise a plurality of splittable reinforcing filaments or fibers. 21.The construct of claim 18, wherein the plurality of reinforcingfilaments or fibers further comprise a super absorbent polymercomposition.